Device for converting tuning fork vibration to rotary motion



Dec. 24, 1968 R. SIEFERT 3,417,632

DEVICE FOR CONVERTING TUNING FORK VIBRATION TO ROTARY MOTION Filed April 24. 1967 Fig. I

United States Patent many Filed Apr. 24, 1967, Ser. No. 633,223 Claims priority, applicati9on germany, Apr. 22, 1966, 5 06 5 Claims. (01. 74-142 ABSTRACT OF THE DISCLOSURE One tine of a timepiece tuning fork carries a bearing for one end of a ratchet wheel shaft and, if desired, a detaining pawl engaging on the wheel to prevent backward rotation of the wheel and shaft, while the other time carries at least one drive pawl for engagement with the wheel to impart forward rotation. The other end of the shaft is held in virtually fixed location where it provides a takeoff for a work train.

Background of the invention:

(a) Field of the invention-This is a pawled system for utilization of an externally driven time gear to power a clockwork.

(b) Description of the prior art.There are devices known wherein a push pawl for coacting with a ratchet stepping wheel is mounted on a tuning fork tine and the wheel is bearingly mounted in fixed position on a framework and a detaining pawl for the wheel is also mounted on the framework. Such a device is found in German Auslegeschrift 1,034,551. These stepping devices are extremely diificult to adjust to satisfactory operating condition, because the pawl mounted on the fork tine must be fitted to the wheel in a predetermined angular and longitudinal relationship.

Moreover, the detaining pawl must be justified in reference to the wheel. If a tuning fork having a pawl thereon is removed from its place near the stepping wheel, great care must be exercised less the pawl become bent or otherwise damaged. After a remounting of the oscillatory system the stepping action must be justified anew because the relative position of the tuning fork and the stepping wheel never corresponds to that originally obtained. This justification work can be done only by especially trained expert craftsmen.

Summary of the invention The invention is a device for conversion of the vibrational movement of a tuning fork into a successively stepped movement of rotation, comprising a ratchet wheel whose shaft or arbor is bearingly mounted on one of the tines of a fork and has at least one drive pawl mounted on the other tine. If a detaining pawl is necessary, then it must be carried on the tine carrying the shaft. Two drive pawls may be used instead of a detaining pawl and one drive pawl. In such a case both pawls are mounted on one tine and the wheel is bearingly mounted on the other, one of the pawls acting as a push pawl and the other as a clawed pulling pawl. The shaft carries the ratchet wheel 3,417,632 Patented Dec. 24, 1968 near the shaft bearing on the one tine and carries a takeolf pinion near the other end of the shaft which is bearingly mounted in substantially a fixed location.

Drawing FIG. 1 is a side view of the device, and

FIG. 2 is a sectional View of the device, the section being taken substantially along the dotted line of FIG. 1 and looking leftward on the section.

Description of the preferred embodiments The tuning fork 1 mounted on a clockwork frame 10 is driven by means (not shown) to maintain the tines 2 and 3 in a state of vibration. One tine such as 2 has mounted fast thereon a bracket 6a provided with a bearing 6 for mounting an arbor 8 at one end 8b thereof, which end is provided with a ratchet wheel 4. The other tine 3 carries, by means of a bracket member 3a, a push or drive pawl 5 engaging on the wheel 4. By means of an arm 6b the bracket 6a, or essentially the tine 2, has mounted thereon a detaining pawl 7. Instead of the detaining pawl 7 a clawed pulling pawl 7 moving in the same direction, but mounted on the tine 3 by means of the member 3a may be provided to give double action. The two actions are preferably displaced by a phase angle of The end 8a. of the arbor -8 opposite from the wheel and bearing 6 carries a pinnion 11 and is bearingly mounted, as at 9 on the frame 10 of a clockwork. Thus, while the wheel end 8b of the arbor is subjected to vibration the pinion end of the arbor is essentially in fixed position, so that rotary movement of the arbor and pinion can be transmitted to the gear train as at 12 with no disturbing influences.

The invention provides a unitary structure made up of the tuning fork and the stepping device including the arbor and pinion. This unit is completely interchangeable and lends itself to being repaired. If the oscillatory system is removed the stepping device needs no justifying.

The invention has the advantage over the hitherto known devices of this nature in that the stroke of the push pawl relative to the wheel is doubled which enables power takeoff from the tuning fork comparatively near its node of vibration.

I claim:

1. A device for the conversion of vibratory motion into repeated unidirectional turning movements comprising a tuning fork mounted for vibration and having two tines, bearing means mounted on one of said tines, an arbor rotatably mounted in said bearing means at one end portion of the arbor, a ratchet wheel mounted on the arbor, and a drive pawl mounted on the other tine and engaging on the wheel.

2. A device as claimed in claim 1 and a detaining pawl mounted on said one of the tines.

3. A device as claimed in claim 1, said other tine carrying an additional pulling pawl and the first mentioned drive pawl being a push pawl, both engaging on the wheel.

4. A device as claimed in claim 1 said other tine carrying an additional pawl engaging 0n the wheel and the two pawls being phase displaced 90 so that one acts as the drive pawl and the other subsequently acts as a detaining pawl.

5. A device as claimed in claim 1, a substantially stationary framework having the tuning fork mounted 3 thereon, and second bearing means on the framework for rotatably mounting the other end of the arbor in a substantially fixed position relative to the framework, and a power takeoff pinnion fast on the arbor remote from the first mentioned bearing means and toward the second.

References Cited UNITED STATES PATENTS 2,960,817 11/1960 Hetzel 74--142 XR 4 2,971,323 2/1961 Hetzel 58-23 3,107,481 10/1963 Oram 58-23 3,184,981 5/1965 Bennett et a1. 74142 US. Cl. X.R. 

